by R Paul Carey
It's my understanding the NTSB is expected to issue its Preliminary Report tomorrow, February 23.
Railroad Forums
RandallW wrote: ↑Wed Feb 22, 2023 5:36 am If ECP braking were installed, wouldn't it have caused all cars to brake at as close to the same time as possible given the speed of light instead of leading cars braking before trailing cars?
taracer wrote: ↑Wed Feb 22, 2023 8:20 am Yes, the "signal" to apply, or release the brakes, would be practically instantaneous with ECP brakes. On the giant PSR trains run today, I can count with my hands how long the signal takes to travel, the air being that signal. It's even slower in cold weather, like nowWould it? How long does it now take to walk and correctly inspect a 1.5 mile long consist? Would that still be necessary with a competent ECP+ system with diagnostics on each piece of rolling stock? Automobiles have had brake-wear sensors for years; why not rolling stock? [What exactly does FRA require be inspected during that walk?] Such a system could test-cycle the brakes at initial startup.
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That instant setup on all cars would certainly reduce the forces evolved, but that would add complexity and more inspections to make sure the system is working on the cars themselves since they take a lot of abuse.
It would require more people and more downtime and once again, PSR can't have any of that.
QB 52.32 wrote: ↑Wed Feb 22, 2023 12:38 pm consider replacing rail-based technology with ascending truck-based autonomous technology to some greater or lesser degree?Such would eliminate the actual advantages rail DOES have; foremost being fuel efficiency. Second: even assuming you can get acceptance of autonomous trucks; when one breaks down, it can't just coast over to the shoulder, & the line stops until it can be removed.
farecard wrote: ↑Wed Feb 22, 2023 10:41 am Would it? How long does it now take to walk and correctly inspect a 1.5 mile long consist? Would that still be necessary with a competent ECP+ system with diagnostics on each piece of rolling stock? Automobiles have had brake-wear sensors for years; why not rolling stock? [What exactly does FRA require be inspected during that walk?] Such a system could test-cycle the brakes at initial startup.Lets see... RP2040 microcontroller at 73.5 cents (bulk rate reel of 3400), temperature sensor $3.16 (100+ bulk rate), rotation sensor, relays... I mean, you could wire up each axle for $20 per axle, and as the controlling system in the engine pings the controller bus to make sure everything's OK. If it's not, you get a "car 78, truck 1, axle 2, temps hot" (example). I'm mean, it'll not be a "lp1 on fire" error but at least you know where specifically to look. Besides, if the sensors fail, yank the car out, it's a defect.
Yes, it would more complex to design, but to run? (How much do you need to know about the BIOS diagnosis on your laptop? It runs, your box boots, or fails with an error message.) I can easily see the FRA allowing one car with marginal/failed brakes iffin it was in a 50+ car consist of a given weight, etc.
And once you have a per-car microcontroller, hot box sensors are almost trivial. So would be car weight sensing, and antilock braking; that would reduce wheel wear $$$. Further, on non-emergency brake applications, the system could start blended braking at the rear and move forward car by car, keeping the train taunt, if that's desired.
I see the railroad industry as in a place rather like the Bell System was decades ago; Ma stubbornly stuck to "We've always done it that way; why change now?" until it collapsed under its own weight. Yes, there are significant differences but also parallels.
What do you do when a train carrying toxic chemicals crashes in your town?
East Palestine, Ohio, is finding out the hard way.
The train derailed earlier this month, but the mess still hasn’t been cleaned up. Now officials are playing the blame game, with East Palestine residents stuck in the middle.
What’s next for East Palestine residents? Trains roll through America’s small towns every day. So who’s responsible when things go so wrong?
R Paul Carey wrote: ↑Wed Feb 22, 2023 10:31 am It's my understanding the NTSB is expected to issue its Preliminary Report tomorrow, February 23.For those that choose not to review our previous pages of the EP derailment discussion:
farecard wrote: ↑Wed Feb 22, 2023 1:34 pmIf a magic wand can be waved about fully implementing ECP brake technology, why then make negative assumptions about an ascendant well-resourced truck-based technology with the biggest disadvantage application to public shared rights-of-way?consider replacing rail-based technology with ascending truck-based autonomous technology to some greater or lesser degree?Such would eliminate the actual advantages rail DOES have; foremost being fuel efficiency. Second: even assuming you can get acceptance of autonomous trucks; when one breaks down, it can't just coast over to the shoulder, & the line stops until it can be removed.
STrRedWolf wrote: ↑Wed Feb 22, 2023 3:53 pm Lets see... RP2040 microcontroller at 73.5 cents (bulk rate reel of 3400), temperature sensor $3.16 (100+ bulk rate), rotation sensor, relays... I mean, you could wire up each axle for $20 per axle, and as the controlling system in the engine pings the controller bus to make sure everything's OK. If it's not, you get a "car 78, truck 1, axle 2, temps hot" (example). I'm mean, it'll not be a "lp1 on fire" error but at least you know where specifically to look. Besides, if the sensors fail, yank the car out, it's a defect.I think that $20 per axle suggestion wouldn't last a month, tops.
Ken Rice wrote: ↑Wed Feb 22, 2023 7:04 pm Yup. And the connectors to establish the communication bus down the length of the 100+ car train have to work reliably, not flake out when a little dirt gets in, etc.Yes, you'll need reliable connectors, but that's hardly rocket science. What do the in-use systems in AU, etc use? Start with existing ones, such as between semi trucks and trailers.
And then there’s power to run those electronics. Every car will need a battery.Nope, no batteries required; perhaps we float a battery in each to help bridge spikes. But we have POE now. A train-net wire system could easily carry power and signal, say over spread spectrum. It does not need to be that fast.
It’s not a simple or cheap problem. I completely understand why railroads would rather stick with the current simple but very reliable mechanical solution.What worked well for 50 car consists has far more limitations when you double the length. Ask the crew of UP MGRCY04 how reliable air brakes are.
NYCRRson wrote: ↑Wed Feb 22, 2023 9:11 pmReducing the energy is the goal, like crumple zones in automobiles. We all know the cars won't stop instantly, but if the forces are reduced when they hit due to slower speeds, the less chance of a breech.
I will never be convinced that applying all the brakes instantaneously (ECP) after a bearing/axle burns off near the front of the train will reduce the damages from a derailment very much,,, Cars are going to derail and pile up, the braking force on the cars is not enough to stop every rail car instantaneously in place when the brakes are applied.
The only way to immediately stop all rail cars in a train when a problem is detected is to have about 20 axles with multiple brake discs (about 8 per axle) on all axles under every car in the train.,, And all that stopping force would transfer into the rails and ties and simply result is the whole length of the train being on top of shattered roadbed with turned over rails and fractured ties. That would simply spread the destruction along the whole length of the train.